METHOD FOR ETCHING SILICON SUBSTRATE

摘要

A method for etching a silicon substrate is disclosed wherein no residue is left even when a wide area is etched and finished side walls are generally vertical. The method comprises a mask-forming step wherein an etching mask is formed on the surface of a silicon substrate; a mounting step wherein the silicon substrate is mounted on a stage; an etching step wherein the silicon substrate surface is dry-etched through opening portions of the etching mask using an etching gas which is transformed into a plasma by high-frequency power, thereby forming a certain structured surface; and a protective film-forming step wherein a protective film is formed on the thus-formed structured surface using a protective film-forming gas which is transformed into a plasma by high-frequency power. In this connection, after sequentially performing the mask-forming step and the mounting step, the etching step and the protective film-forming step are alternately repeated and a high-frequency power of 100-600 KHz is applied to the stage during the etching step.